import React, { Component } from 'react';

export default class Demo extends Component {
    state = {count: 0}
    add = ()=>{
        //对象式的setState
        //1. 获取原来的count值
        // const {count} = this.state
        //2. 更新状态
        // this.setState({count: count+1},()=>{
        //     console.log(this.state.count)
        // })

        //函数式的setState
        this.setState(state => ({count: state.count+1}))
    }
  render() {
    return <div>
        <h1>当前求和为：{this.state.count}</h1>
        <button onClick={this.add}>点我+1</button>
    </div>;
  }
}
